entity-framework - 在LINQ中将字符串转换为int到实体？

Question

我必须将string值转换为int，但是似乎LINQ to Entities不支持此功能。

对于以下代码，出现错误。

var query = (from p in dc.CustomerBranch
             where p.ID == Convert.ToInt32(id) // here is the error.
             select new Location()
             {
                 Name      = p.BranchName,
                 Address   = p.Address,
                 Postcode  = p.Postcode,
                 City      = p.City,
                 Telephone = p.Telephone
             }).First();
return query;

LINQ to Entities does not recognize the method 'Int32 ToInt32 (System.String)', and this method can not be translated into a store expression.

Answer 1

在LINQ之外进行转换:

var idInt = Convert.ToInt32(id);
var query = (from p in dc.CustomerBranch
             where p.ID == idInt 
             select new Location()
             {
                 Name      = p.BranchName,
                 Address   = p.Address,
                 Postcode  = p.Postcode,
                 City      = p.City,
                 Telephone = p.Telephone
             }).First();
return query;